Over the past several decades, radio communications have significantly impacted the ways in which people go about their daily lives. Sensor systems use radio communications to exchange data and commands. People use radio communications to chat with other people (e.g., via voice calls, texting, instant messaging, video calls, etc.), stream videos, listen to music, download information, send/receive photos, etc. Such a wide variety of different types of radio communications typically have a wide range of requirements. Efficient, flexible, and low cost designs capable of meeting all of these requirements are desirable, and will be important for meeting future radio communication demands.
One way wireless devices strive to meet such requirements is through the use of pilot or reference signals, which are transmitted by a transmitter and known by a receiver. Radio signals experience various distortions when propagated from the transmitter to the receiver via radio propagation channels. The transmission of the pilot or reference signals, e.g., with the data signals, enables the receiver to more accurately recover the transmitted signal. More particularly, the receiver uses the known pilot/reference signal(s) to estimate the radio channel between the transmitter and the receiver, and uses the estimated radio channel to perform equalization on the data signal to accurately recover the transmitted data signal. Because the receiver relies heavily on pilot/reference signals to accurately process received data, and because the use of such pilot/reference signals requires a fair amount of overhead, there is much interest in optimizing the use of such signals.